kernel.git/arch/x86/Makefile, branch linux-6.15.y

Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2025-04-05T22:46:50Z

Pull Kbuild updates from Masahiro Yamada: - Improve performance in gendwarfksyms - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS - Support CONFIG_HEADERS_INSTALL for ARCH=um - Use more relative paths to sources files for better reproducibility - Support the loong64 Debian architecture - Add Kbuild bash completion - Introduce intermediate vmlinux.unstripped for architectures that need static relocations to be stripped from the final vmlinux - Fix versioning in Debian packages for -rc releases - Treat missing MODULE_DESCRIPTION() as an error - Convert Nios2 Makefiles to use the generic rule for built-in DTB - Add debuginfo support to the RPM package * tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits) kbuild: rpm-pkg: build a debuginfo RPM kconfig: merge_config: use an empty file as initfile nios2: migrate to the generic rule for built-in DTB rust: kbuild: skip `--remap-path-prefix` for `rustdoc` kbuild: pacman-pkg: hardcode module installation path kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally modpost: require a MODULE_DESCRIPTION() kbuild: make all file references relative to source root x86: drop unnecessary prefix map configuration kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS kbuild: Add a help message for "headers" kbuild: deb-pkg: remove "version" variable in mkdebian kbuild: deb-pkg: fix versioning for -rc releases Documentation/kbuild: Fix indentation in modules.rst example x86: Get rid of Makefile.postlink kbuild: Create intermediate vmlinux build with relocations preserved kbuild: Introduce Kconfig symbol for linking vmlinux with relocations kbuild: link-vmlinux.sh: Make output file name configurable kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y Revert "kheaders: Ignore silly-rename files" ...

x86: don't re-generate cpufeaturemasks.h so eagerly

2025-03-31T21:19:55Z

It turns out the code to generate the x86 cpufeaturemasks.h header was way too aggressive, and would re-generate it whenever the timestamp on the kernel config file changed. Now, the regular 'make *config' tools are fairly careful to not rewrite the kernel config file unless the contents change, but other usecases aren't that careful. Michael Kelley reports that 'make-kpkg' ends up doing "make syncconfig" multiple times in prepping to build, and will modify the config file in the process (and then modify it back, but by then the timestamps have changed). Jakub Kicinski reports that the netdev CI does something similar in how it generates the config file in multiple steps. In both cases, the config file timestamp updates then cause the cpufeaturemasks.h file to be regenerated, and that in turn then causes lots of unnecessary rebuilds due to all the normal dependencies. Fix it by using our 'filechk' infrastructure in the Makefile to generate the header file. That will only write a new version of the file if the contents of the file have actually changed. Fixes: 841326332bcb ("x86/cpufeatures: Generate the header based on build config") Reported-by: Michael Kelley Reported-by: Jakub Kicinski Link: https://lore.kernel.org/all/SN6PR02MB415756D1829740F6E8AC11D1D4D82@SN6PR02MB4157.namprd02.prod.outlook.com/ Link: https://lore.kernel.org/all/20250328162311.08134fa6@kernel.org/ Cc: Peter Anvin Signed-off-by: Linus Torvalds

Merge tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-03-25T05:06:11Z

Pull core x86 updates from Ingo Molnar: "x86 CPU features support: - Generate the header based on build config (H. Peter Anvin, Xin Li) - x86 CPUID parsing updates and fixes (Ahmed S. Darwish) - Introduce the 'setcpuid=' boot parameter (Brendan Jackman) - Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan Jackman) - Utilize CPU-type for CPU matching (Pawan Gupta) - Warn about unmet CPU feature dependencies (Sohil Mehta) - Prepare for new Intel Family numbers (Sohil Mehta) Percpu code: - Standardize & reorganize the x86 percpu layout and related cleanups (Brian Gerst) - Convert the stackprotector canary to a regular percpu variable (Brian Gerst) - Add a percpu subsection for cache hot data (Brian Gerst) - Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak) - Construct __percpu_seg_override from __percpu_seg (Uros Bizjak) MM: - Add support for broadcast TLB invalidation using AMD's INVLPGB instruction (Rik van Riel) - Rework ROX cache to avoid writable copy (Mike Rapoport) - PAT: restore large ROX pages after fragmentation (Kirill A. Shutemov, Mike Rapoport) - Make memremap(MEMREMAP_WB) map memory as encrypted by default (Kirill A. Shutemov) - Robustify page table initialization (Kirill A. Shutemov) - Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn) - Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW (Matthew Wilcox) KASLR: - x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir Singh) CPU bugs: - Implement FineIBT-BHI mitigation (Peter Zijlstra) - speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta) - speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan Gupta) - RFDS: Exclude P-only parts from the RFDS affected list (Pawan Gupta) System calls: - Break up entry/common.c (Brian Gerst) - Move sysctls into arch/x86 (Joel Granados) Intel LAM support updates: (Maciej Wieczor-Retman) - selftests/lam: Move cpu_has_la57() to use cpuinfo flag - selftests/lam: Skip test if LAM is disabled - selftests/lam: Test get_user() LAM pointer handling AMD SMN access updates: - Add SMN offsets to exclusive region access (Mario Limonciello) - Add support for debugfs access to SMN registers (Mario Limonciello) - Have HSMP use SMN through AMD_NODE (Yazen Ghannam) Power management updates: (Patryk Wlazlyn) - Allow calling mwait_play_dead with an arbitrary hint - ACPI/processor_idle: Add FFH state handling - intel_idle: Provide the default enter_dead() handler - Eliminate mwait_play_dead_cpuid_hint() Build system: - Raise the minimum GCC version to 8.1 (Brian Gerst) - Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor) Kconfig: (Arnd Bergmann) - Add cmpxchg8b support back to Geode CPUs - Drop 32-bit "bigsmp" machine support - Rework CONFIG_GENERIC_CPU compiler flags - Drop configuration options for early 64-bit CPUs - Remove CONFIG_HIGHMEM64G support - Drop CONFIG_SWIOTLB for PAE - Drop support for CONFIG_HIGHPTE - Document CONFIG_X86_INTEL_MID as 64-bit-only - Remove old STA2x11 support - Only allow CONFIG_EISA for 32-bit Headers: - Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI headers (Thomas Huth) Assembly code & machine code patching: - x86/alternatives: Simplify alternative_call() interface (Josh Poimboeuf) - x86/alternatives: Simplify callthunk patching (Peter Zijlstra) - KVM: VMX: Use named operands in inline asm (Josh Poimboeuf) - x86/hyperv: Use named operands in inline asm (Josh Poimboeuf) - x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra) - x86/kexec: Merge x86_32 and x86_64 code using macros from (Uros Bizjak) - Use named operands in inline asm (Uros Bizjak) - Improve performance by using asm_inline() for atomic locking instructions (Uros Bizjak) Earlyprintk: - Harden early_serial (Peter Zijlstra) NMI handler: - Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus() (Waiman Long) Miscellaneous fixes and cleanups: - by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar, Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner, Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly Kuznetsov, Xin Li, liuye" * tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits) zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault x86/asm: Make asm export of __ref_stack_chk_guard unconditional x86/mm: Only do broadcast flush from reclaim if pages were unmapped perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones perf/x86/intel, x86/cpu: Simplify Intel PMU initialization x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions x86/asm: Use asm_inline() instead of asm() in clwb() x86/asm: Use CLFLUSHOPT and CLWB mnemonics in x86/hweight: Use asm_inline() instead of asm() x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm() x86/hweight: Use named operands in inline asm() x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP x86/head/64: Avoid Clang < 17 stack protector in startup code x86/kexec: Merge x86_32 and x86_64 code using macros from x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro x86/cpu/intel: Limit the non-architectural constant_tsc model checks x86/mm/pat: Replace Intel x86_model checks with VFM ones x86/cpu/intel: Fix fast string initialization for extended Families ...

x86/cpufeatures: Generate the header based on build config

2025-03-19T10:15:11Z

Introduce an AWK script to auto-generate the header with required and disabled feature masks based on and the current build config. Thus for any CPU feature with a build config, e.g., X86_FRED, simply add: config X86_DISABLED_FEATURE_FRED def_bool y depends on !X86_FRED to arch/x86/Kconfig.cpufeatures, instead of adding a conditional CPU feature disable flag, e.g., DISABLE_FRED. Lastly, the generated required and disabled feature masks will be added to their corresponding feature masks for this particular compile-time configuration. [ Xin: build integration improvements ] [ mingo: Improved changelog and comments ] Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li (Intel) Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Ingo Molnar Reviewed-by: Nikolay Borisov Cc: Linus Torvalds Link: https://lore.kernel.org/r/20250305184725.3341760-3-xin@zytor.com

kbuild: Introduce Kconfig symbol for linking vmlinux with relocations

2025-03-16T15:29:50Z

Some architectures build vmlinux with static relocations preserved, but strip them again from the final vmlinux image. Arch specific tools consume these static relocations in order to construct relocation tables for KASLR. The fact that vmlinux is created, consumed and subsequently updated goes against the typical, declarative paradigm used by Make, which is based on rules and dependencies. So as a first step towards cleaning this up, introduce a Kconfig symbol to declare that the arch wants to consume the static relocations emitted into vmlinux. This will be wired up further in subsequent patches. Signed-off-by: Ard Biesheuvel Signed-off-by: Masahiro Yamada

hardening: Enable i386 FORTIFY_SOURCE on Clang 16+

2025-03-08T17:16:42Z

The i386 regparm bug exposed with FORTIFY_SOURCE with Clang was fixed in Clang 16[1]. Link: https://github.com/llvm/llvm-project/commit/c167c0a4dcdb998affb2756ce76903a12f7d8ca5 [1] Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/r/20250308042929.1753543-2-kees@kernel.org Signed-off-by: Kees Cook

x86/build: Remove -ffreestanding on i386 with GCC

2025-03-08T17:16:41Z

The use of -ffreestanding is a leftover that is only needed for certain versions of Clang. Adjust this to be Clang-only. A later patch will make this a versioned check. Acked-by: Ingo Molnar Reviewed-by: Nathan Chancellor Link: https://lore.kernel.org/r/20250308042929.1753543-1-kees@kernel.org Signed-off-by: Kees Cook

Merge branch 'x86/cpu' into x86/asm, to pick up dependent commits

2025-03-04T10:19:21Z

Signed-off-by: Ingo Molnar

x86/cpu: Drop configuration options for early 64-bit CPUs

2025-02-27T10:19:06Z

The x86 CPU selection menu is confusing for a number of reasons: When configuring 32-bit kernels, it shows a small number of early 64-bit microarchitectures (K8, Core 2) but not the regular generic 64-bit target that is the normal default. There is no longer a reason to run 32-bit kernels on production 64-bit systems, so only actual 32-bit CPUs need to be shown here. When configuring 64-bit kernels, the options also pointless as there is no way to pick any CPU from the past 15 years, leaving GENERIC_CPU as the only sensible choice. Address both of the above by removing the obsolete options and making all 64-bit kernels run on both Intel and AMD CPUs from any generation. Testing generic 32-bit kernels on 64-bit hardware remains possible, just not building a 32-bit kernel that requires a 64-bit CPU. Signed-off-by: Arnd Bergmann Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/20250226213714.4040853-5-arnd@kernel.org

x86/build: Rework CONFIG_GENERIC_CPU compiler flags

2025-02-27T10:19:05Z

Building an x86-64 kernel with CONFIG_GENERIC_CPU is documented to run on all CPUs, but the Makefile does not actually pass an -march= argument, instead relying on the default that was used to configure the toolchain. In many cases, gcc will be configured to -march=x86-64 or -march=k8 for maximum compatibility, but in other cases a distribution default may be either raised to a more recent ISA, or set to -march=native to build for the CPU used for compilation. This still works in the case of building a custom kernel for the local machine. The point where it breaks down is building a kernel for another machine that is older the the default target. Changing the default to -march=x86-64 would make it work reliable, but possibly produce worse code on distros that intentionally default to a newer ISA. To allow reliably building a kernel for either the oldest x86-64 CPUs, pass the -march=x86-64 flag to the compiler. This was not possible in early versions of x86-64 gcc, but works on all currently supported versions down to at least gcc-5. Signed-off-by: Arnd Bergmann Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/20250226213714.4040853-4-arnd@kernel.org